C541U Datasheet, PDF (7/63 Pages) Siemens Semiconductor Group – 8 BIT CMOS MICROCONTROLLER

C541U
Table 1
Pin Definitions and Functions
Symbol
Pin I/O*) Function
Numbers
P-LCC-44
D+
3
I/O USB D+ Data Line
The pin D+ can be directly connected to USB cable (transceiver
is integrated on-chip).
D-
4
I/O USB D- Data Line
The pin D- can be directly connected to USB cable (transceiver is
integrated on-chip).
P1.0 - P1.4 5 - 7,
I/O
12, 34, 44
5
6
7
12
34
44
Port 1
is an 6-bit quasi-bidirectional I/O port with internal pullup
resistors. Port 1 pins that have 1’s written to them are pulled high
by the internal pullup resistors, and in that state can be used as
inputs. As inputs, port 1 pins being externally pulled low will
source current (I _IL, in the DC characteristics) because of the
internal pullup resistors.
Port 1 also contains two outputs with LED drive capability as well
as the four pins of the SSC. The pins with LED drive capability are
able to sink current up to 10 mA. The output latch corresponding
to a secondary function must be programmed to a one (1) for that
function to operate (except when used for the compare functions).
The secondary functions are assigned to the port 1 pins as
follows :
P1.0 / LED0 LED0 output
P1.1 / LED1 LED1 output
P1.2 / SCLK SSC Master Clock Output /
SSC Slave Clock Input
P1.3 / SRI SSC Receive Input
P1.4 / STO SSC Transmit Output
P1.5 / SLS SSC Slave Select Inp.
RESET
10
*) I = Input
O = Output
I
RESET
A high level on this pin for the duration of two machine cycles
while the oscillator is running resets the C541U. A small internal
pulldown resistor permits power-on reset using only a capacitor
connected to V_DD .
Semiconductor Group
5